HTC sync issueSupport

I am using HTC desire S for over a year now with no issues. I have been also using HTC Sync and managed to synchronize my contacts and calendar with microsoft outlook.

However, I have been trying for the past few todays to sync my phone and while the synchronisation screen together with the sync bar (on the top right) appear and the synchronisation starts, the HTC sync says that no device is connected. If I do nothing, the synchonisation screen appears again and the sync starts once more. It then again, says no device is connected and it goes on.

Have tried restarting both the PC and the phone with no luck. Have also checked my USB cable, again no luck. Any ideas please?